Beach sand pattern at low tide near Richmond Pond west from Acoaxet at evening. Westport, Massachusetts, November 15, 2004
Sand pattern at rising tide at the tip of Horseneck Point. Westport, Massachusetts, February 1, 2005.
Remnants of ancient ingenious intertidal stone fish traps (rows of beachrock stone arranged in walls in semi-circular patterns) at low tide in Al Aaliya Island (Jazirat al Aliyah). Qatar, March 27, 2013
Intricate patterns in the sand that are wave-formed ripples (also known as oscillation ripples), which provide a frozen snapshot of the water s movement just before the tide or water level receded. They are formed by the back-and-forth oscillatory motion of water particles at the bottom of shallow waves. As a wave passes, water moves sand grains forward and then backward, piling them into these neat, parallel ridges. The crests (ridges) of the ripples run parallel to the shoreline, which is typical for wave-formed ripples as they align perpendicular to the direction of wave propagation. The preservation of such sharp ripple crests indicates the water receded gently, likely during a calm period after the windier conditions that initially formed them. Sestroretsk near Saint Petersburg, Russia, October 9, 2025